I am on lab 1a, and I have completed the lab but I can't download the Grader app. Whether or not I am logged into Salesforce on a different tab, It shows the screenshot attached whenever I try to log in from the link on this website. I have tried everything log in-wise, I'm copy and pasting my username and password so I know it's correct, it just won't let me log in using the link from MaxzPlace. The only time I have successfully logged in was through the emailed link; is there any way to download the Grader app through the Salesforce account?

Yeah so that's an issue with your browser. Can you try a different one and make sure you're using the browser settings given at the top of the Lab 1a cover sheet? Then let me know, ok?